BMS Derivatives C7-Linked to β-Cyclodextrin and Hyperbranched Polyglycerol Retain Activity against R5-HIV-1NLAD8 Isolates and Can Be Deemed Potential Microbicides

Amides from indole-3-glyoxylic acid and 4-benzoyl-2-methylpiperazine, which are related to entry inhibitors developed by Bristol-Myers Squibb (BMS), have been synthesized with aliphatic chains located at the C7 position of the indole ring. These spacers contain an azido group suitable for the well-known Cu(I)-catalyzed (3+2)-cycloaddition or an activated triple bond for the nucleophilic addition of thiols under physiological conditions. Reaction with polyols (β-cyclodextrin and hyperbranched polyglycerol) decorated with complementary click partners has afforded polyol-BMS-like conjugates that are not cytotoxic (TZM.bl cells) and retain the activity against R5-HIV-1_NLAD8 isolates. Thus, potential vaginal microbicides based on entry inhibitors, which can be called of 4^th generation, are reported here for the first time.     

Introducing four different branch structures in PET by reactive processing––A rheological investigation

Chain extension/branching by reactive processing is a well-known method to enhance the rheological properties of polymers. In this study, pyromellitic dianhydride, poly(glycolic acid), triglycidyl isocyanurate, and bisphenol A diglycidyl ether were used as chain extender/branching agents to produce branched Polyethylene terephthalate (PETs) with four different molecular structures. According to the linear rheological characterizations, the storage modulus and complex viscosity of modified PET samples enhanced significantly after branching. The shear viscosities of modified PET show a pronounced shear-thinning behavior and a remarkable increase at low frequencies, which can be an indication of the existence of long-chain branches (LCBs) in the molecular structure of polymer and broadening the molecular weight distribution. Fourier transform infrared (FTIR) and differential scanning calorimetry (DSC) analysis were used to investigate the effect of branching agents on the chemical structure and thermal properties of PET, respectively. DSC results show that higher amounts of LCBs lead to lower melting and crystallization temperatures.     

超支化聚合物对羊毛织物的改性研究

为了改善羊毛织物的防毡缩性能,利用三羟甲基磷(THP)交联作用,将端氨基超支化聚合物(HBP-NH2)共价结合到羊毛纤维上,并测试整理后织物防毡缩、抗菌和染色性能及断裂强力变化。结果表明:单独使用超支化聚合物处理,羊毛织物的毡缩率由20.69%下降到17.31%,未达到羊毛织物防毡缩的目的;而经三羟甲基磷/超支化聚合物处理后,羊毛织物的毡缩率下降到7.43%,达到机可洗标准;且抑菌率达92.37%,低温条件下羊毛织物的染色性能也得到明显改善。     

Core–shell type multi‐arm azide polymers based on hyperbranched copolyether as potential energetic materials in solid propellants

A series of novel multi‐arm azide copolymers (POGs) with the same hyperbranched poly[3‐ethyl‐3‐(hydroxymethyl)oxetane] core (PEHO‐c) and different content of linear glycidyl azide polymer shell (GAP‐s) have been synthesized by sequential cationic ring‐opening polymerization and azidation. Detailed structural information of these copolyethers was deduced from Fourier transform infrared, ¹H NMR and inverse gated decoupled ¹³C NMR spectroscopies, matrix‐assisted laser desorption ionization time‐of‐flight mass spectrometry, gel permeation chromatography and elemental analysis. The molecular weight of POG having GAP‐s and PEHO‐c with a molar ratio 14.95:1 (R_s/c) was around 31 000 g mol^?1, far above that of linear GAP (around 4000 g mol^?1). The apparent viscosity and glass transition temperature (?51 to ?23 °C) decreased first and then slightly increased with increasing molecular weight. Thermal analysis revealed that all the obtained POGs exhibited excellent resistance to thermal decomposition up to 220 °C. Moreover, the energetic properties, investigated using oxygen bomb calorimetric measurements, indicated that the enthalpy of formation of the POGs was higher than that of general linear GAP, but similar to that of branched GAP under reasonable R_s/c. The compatibilities of the POGs with common materials used in solid propellants were studied using differential scanning calorimetry and the results indicated that the POGs had good compatibility with these materials. © 2017 Society of Chemical Industry     

Improved thermosets obtained from diglycidyl ether of bisphenol A/4,4′‐diaminodiphenylsulfone based on a new epoxy‐terminated hyperbranched polymer

A new hyperbranched polymer (HBP) with a flexible aromatic skeleton and terminal epoxy groups was synthesized to improve the toughness of diglycidyl ether of bisphenol A. The HBP was characterized using nuclear magnetic resonance, Fourier transfer infrared spectroscopy and gel permeation chromatography. The effect of HBP on the thermomechanical and mechanical properties of modified epoxy systems was studied. For evaluating the efficiency of the modified epoxy systems, composite samples using glass fiber cloth were molded and tested. Using dynamic mechanical analysis, a slight reduction in glass transition temperature (T_g) with increasing HBP content was observed. Analysis of fracture surfaces revealed a possible effect of HBP as a toughener and showed no phase separation in the modified resin systems. The results showed that the addition of 15 phr HBP maximized the toughness of the modified resin systems with 215 and 40% increases in impact and flexural strengths, respectively. T_g and heat resistance of cured modified resin systems decreased slightly with an increase in HBP content and, at 15 phr HBP, only a 2.6% decrease in thermomechanical properties was observed. Meanwhile, a molded composite with HBP showed improved mechanical properties and retention rate at 150 °C as compared to that made with neat resin. © 2015 Society of Chemical Industry     

Effect of hyperbranched poly(citric polyethylene glycol) with various polyethylene glycol chain lengths on starch plasticization and retrogradation

A series of hyperbranched poly(citric polyethylene glycol) (PCPEG) materials with varied polyethylene glycol (PEG) chain lengths as plasticizers were mixed with maize starch (MS) via cooking and film‐forming. The structure, pasting property, plasticization, aging property, moisture absorption and compatibility of plasticized starches were studied by means of Fourier transform infrared spectroscopy, X‐ray diffraction, rapid viscosity analysis, tension testing, moisture absorption measurements and scanning electron microscopy. Compared with PEG and citric acid, PCPEG was more effective in promoting starch chain movement and inhibiting the retrogradation of starch film. Also, PCPEG/MS had smaller moisture content. The longer the plasticizer chain, the better were the aging resistance and moisture resistance of starch. But with an increase of PEG chain length, mechanical properties of PCPEG/MS deteriorated and the compatibility between PCPEG and MS decreased. The hyperbranched derivative of PEG with longer chain exhibited improved plasticization and compatibility with starch. © 2019 Society of Chemical Industry     

Facile synthesis of a castor oil-based hyperbranched acrylate oligomer and its application in UV-curable coatings

Fabrication and performance of the castor oil (CO)-based hyperbranched acrylate (C20AA) UV-curable coatings are highlighted in this work. Herein, C20AA was obtained through a facile reaction of a castor oil-based hyperbranched polyol (C20) with acrylic acid. FT-IR and ¹H NMR spectra confirmed the synthesis of the target C20AA. Subsequently, the as-prepared C20AA was employed for crosslinking a commercialized linear polyurethane acrylate (PUA) UV-curable oligomer. Specifically, by varying the content of C20AA over the range of 0, 20, 40, and 60 wt%, a series of UV-curable coatings were prepared and coded as C20AA-0, C20AA-20, C20AA-40, and C20AA-60, respectively, which were further cured under UV irradiation. The effect of C20AA loadings on the UV-curing efficiency and final polymer performance were investigated. Consequently, the tensile strength, Shore D hardness, pencil hardness, gel content, water resistance, and glass-transition temperature of the UV-cured coatings were greatly improved upon the addition of C20AA. Impressively, with the incorporation of 40 wt% C20AA, the resultant UV-cured coating exhibited highest double bond conversion, superior chemical resistance, and good flexibility. Additionally, all of the coatings showed outstanding transparency and good surface microstructures.     

Stable Light-Emitting Electrochemical Cells Using Hyperbranched Polymer Electrolyte

The choice of an adequate electrolyte is a fundamental aspect in polymer light-emitting electrochemical cells (PLECs) as it provides the in situ electrochemical doping and influences the performance of these devices. In this study, a hyperbranched polymer (Hybrane DEO750 8500) blended with a Li salt is used as a novel electrolyte in state-of-the-art Super Yellow (a polyphenylenevinylene) based LECs. Due to the desirable properties of the hyperbranched polymer and the homogeneous and smooth films that it forms with the emitting polymer, PLEC with excellent electroluminescent properties are obtained using a pulsed current bias scheme. The devices are very stable, with lifetimes in excess of 2000 h with initial luminance values above 450 cd m⁻², a peak efficiency of 12.6 lm W⁻¹, and sub-minute turn-on times. The stability of the devices is also studied by measuring the photoluminescence (PL) of the semiconductor during electroluminescent operation. The findings suggest that it is possible to observe the quenching of the PL in vertically stacked devices due to the advancement of the doped fronts in the film and an immediate PL recovery when the bias is removed.     

Antitumor efficacy of doxorubicin encapsulated within PEGylated poly(amidoamine) dendrimers

We report here a general approach to using poly(amidoamine) (PAMAM) dendrimers modified with polyethylene glycol (PEG) as a platform to encapsulate an anticancer drug doxorubicin (DOX) for in vitro cancer therapy applications. In this approach, PEGylated PAMAM dendrimers were synthesized by conjugating monomethoxypolyethylene glycol with carboxylic acid end group (mPEG‐COOH) onto the surface of generation 5 amine‐terminated PAMAM dendrimer (G5.NH₂), followed by acetylation of the remaining dendrimer terminal amines. By varying the molar ratios of mPEG‐COOH/G5.NH₂, G5.NHAc‐mPEG_n (n = 5, 10, 20, and 40, respectively) with different PEGylation degrees were obtained. We show that the PEGylated dendrimers are able to encapsulate DOX with approximately similar loading capacity regardless of the PEGylation degree. The formed dendrimer/DOX complexes are water soluble and stable. In vitro release studies show that DOX complexed with the PEGylated dendrimers can be released in a sustained manner. Further cell viability assay in conjunction with cell morphology observation demonstrates that the G5.NHAc‐mPEG_n/DOX complexes display effective antitumor activity, and the DOX molecules encapsulated within complexes can be internalized into the cell nucleus, similar to the free DOX drug. Findings from this study suggest that PEGylated dendrimers may be used as a general drug carrier to encapsulate various hydrophobic drugs for different therapeutic applications. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40358.